Where did the change begin?
Labs / Geography
Build a River Delta
A muddy river slows as it meets the still sea and drops its load, piling up new land and splitting into branching distributary channels. Turn the sediment, wave, and tide dials — and drag the river mouth — to see which process wins and what shape the delta takes.
Labs / Geography / Build a River Delta
Build a River Delta
A muddy river slows as it meets the still sea and drops its load, piling up new land and splitting into branching distributary channels. Turn the sediment, wave, and tide dials — and drag the river mouth — to see which process wins and what shape the delta takes.
Why it matters
Why explore this?
Geography explains how places, people, and Earth systems affect one another. This model lets you change one factor and watch its effects spread across space.
Explore
Try the model
Area 0 km²Channels 1Driver RiverShape Birdsfoot
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- Crank sediment high with waves and tide near zero. Why do the channels stretch into long, clawed “birdsfoot” fingers?
- Now push the wave slider up. What happens to those fingers, and why does the coastline round off into a smooth arc?
- Raise the tidal range instead. Why do the channels start running straight out to sea like the bars of an estuary?
- Watch the channel count as the delta grows. When does a single river mouth split into many, and what makes an old channel go quiet?
- Drag the river mouth to a new spot. Where does the sediment go now, and what happens to the delta you already built?
Explain
Make sense of what happened
Connect the pattern to place: identify where the change begins, where its effects appear, and which process links those locations.
Check
Before you leave
What spatial pattern appeared?
Which process connects the cause and effect?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.